Image display apparatuses have been proposed that output respective individual images in different directions on the same display screen (for example, see Japanese Unexamined Patent Publication JP-A2004-206089). When this sort of image display apparatus is for example installed in a vehicle, separate images can be outputted to a driver seat direction and to a passenger seat direction. When viewing the display from the driver seat, the image directed to the passenger seat direction (referred to as a P image) is outputted from the display at such an angle that the image directed to the passenger seat direction cannot be seen normally from the driver seat. When viewing the display from the passenger seat, the image directed to the driver seat direction (referred to as a D image) is outputted at such an angle that the image directed to the driver seat direction cannot be seen normally from the passenger seat.
Specifically, image display apparatuses have been disclosed that are capable of displaying two screens simultaneously with a single liquid crystal display (abbreviated as LCD), and in a vehicle, for example, it is possible to view different screens from the driver seat and from the passenger seat (see Japanese Unexamined Patent Publication JP-A6-186526 (1994) and Japanese Unexamined Patent Publication JP-A 2000-137443). Also, a two screen display apparatus capable of displaying two video images simultaneously on the same screen has been disclosed (see Japanese Unexamined Patent Publication JP-A 11-331876 (1999) and Japanese Unexamined Patent Publication JP-A 9-46622 (1997).
In the conventional art, when, for example, a display is viewed from the driver seat, a portion of the P image may be undesirably visible. Conversely, when the display is viewed from the passenger seat, a portion of the D image may be undesirably visible. The reason for the undesirable visibility is that light emitted from a part of an outer periphery of the display face, as shown in FIG. 22, is reflected by a case wall face 1 disposed near the part of the outer periphery so that the direction in which the light should be outputted is changed, and thus a portion of an image expected to be invisible in the originally non-visible direction is visible. The problem occurs that although each of observers is being allowed to observe an image different from that for the other, the image for the other observer becomes visible, and moreover the images superimposed may be viewed by the observer and thus display quality is reduced.